Airworthiness Directives; Bell Helicopter Textron, Inc., Model 214ST Helicopters

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-SW-26-AD; Amendment 39-9561; AD 96-07-12]

Airworthiness Directives; Bell Helicopter Textron, Inc., Model

214ST Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to Bell Helicopter Textron, Inc. (BHTI) Model 214ST

helicopters with certain tailboom assemblies and a certain emergency

float kit installed, that requires initial and repetitive inspections

of the tailboom for cracks until modifications of the tailboom are

accomplished. This amendment is prompted by several reports of cracks

in the lower aft skin of the tailboom assembly. The actions specified

by this AD are intended to prevent cracks in the tailboom assembly,

which could result in structural failure of the tailboom and subsequent

loss of control of the helicopter.

DATES: Effective May 10, 1996.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of May 10, 1996.

ADDRESSES: The service information referenced in this AD may be

obtained from Bell Helicopter Textron, Inc., Attention: Customer

Support, P.O. Box 482, Fort Worth, Texas 76101. This information may be

examined at the FAA, Office of the Assistant Chief Counsel, 2601

Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the

Federal Register, 800 North Capitol Street NW., suite 700, Washington,

DC.

FOR FURTHER INFORMATION CONTACT: Mr. Charles Harrison, Aerospace

Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office,

2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5447,

fax (817) 222-5959.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (AD) that is applicable to BHTI Model 214ST helicopters,

serial numbers (S/N) 28101 through 28132, with a tailboom assembly,

part number (P/N) 214-031-003-111 or 214-031-003-277, and with an

emergency float kit, P/N 214-706-120, installed, was published in the

Federal Register on November 1, 1995 (60 FR 55495). That action

proposed to require inspections of the tailboom assembly for cracks

within 250 hours time-in-service (TIS) or at the next 180-day float

inspection, and thereafter, at each 180-day float inspection until

certain modifications of the tailboom are accomplished. The

modifications, which are to be accomplished if any crack is found in

the tailboom or on or before accumulating an additional 500 hours TIS

after the effective date of this AD, whichever occurs first, include

installing stiffeners and doublers in the tailboom, and replacing the

access door frame with a thicker access door frame.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. No comments were received on the

proposal or the FAA's determination of the cost to the public. The FAA

has determined that air safety and the public interest require the

adoption of the rule as proposed.

The FAA estimates that six helicopters of U.S. registry will be

affected by this AD, that it will take approximately 20 work hours per

helicopter to accomplish the modifications, approximately 3 work hours

per helicopter to accomplish the 250 hours TIS inspection, and that the

average labor rate is $60 per work hour. Required parts will cost

approximately $1,100 per helicopter. Based on these figures, the total

cost impact of the AD on U.S. operators is estimated to be $14,880.

The regulations adopted herein will not have substantial direct

effects on the

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States, on the relationship between the national government and the

States, or on the distribution of power and responsibilities among the

various levels of government. Therefore, in accordance with Executive

Order 12612, it is determined that this final rule does not have

sufficient federalism implications to warrant the preparation of a

Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) will not have a

significant economic impact, positive or negative, on a substantial

number of small entities under the criteria of the Regulatory

Flexibility Act. A final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it may be obtained

from the Rules Docket at the location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by

reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration amends part 39 of

the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive

to read as follows:

AD 96-07-12 Bell Helicopter Textron, Inc. (BHTI): Amendment 39-

9561. Docket No. 95-SW-26-AD.

Applicability: Model 214ST helicopters, serial number (S/N)

28101 through 28132, with a tailboom assembly, part number (P/N)

214-031-003-111 or 214-031-003-277 and with an emergency float kit,

P/N 214-706-120, installed, certificated in any category.

Note 1: This AD applies to each helicopter identified in the

preceding applicability provision, regardless of whether it has been

modified, altered, or repaired in the area subject to the

requirements of this AD. For helicopters that have been modified,

altered, or repaired so that the performance of the requirements of

this AD is affected, the owner/operator must use the authority

provided in paragraph (d) to request approval from the FAA. This

approval may address either no action, if the current configuration

eliminates the unsafe condition, or different actions necessary to

address the unsafe condition described in this AD. Such a request

should include an assessment of the effect of the changed

configuration on the unsafe condition addressed by this AD. In no

case does the presence of any modification, alteration, or repair

remove any helicopter from the applicability of this AD.

Compliance: Required as indicated, unless accomplished

previously.

To prevent cracks in the tailboom assembly, structural failure

of the tailboom and subsequent loss of control of the helicopter,

accomplish the following:

(a) Within the next 250 hours time-in-service (TIS) or at the

next 180-day float inspection, whichever occurs first, and

thereafter at intervals not to exceed each 180-day float inspection,

visually inspect the tailboom assembly for cracks in accordance with

the maintenance procedures contained in Part 1 of the Accomplishment

Instructions of BHTI Alert Service Bulletin 214ST-95-72, dated July

24, 1995.

(b) Upon discovery of a crack or on or before accumulating an

additional 500 hours TIS after the effective date of this AD,

whichever occurs first, modify the tailboom assembly in accordance

with Part 2 of the Accomplishment Instructions of BHTI Alert Service

Bulletin No. 214ST-95-72, dated July 24, 1995.

(c) Modification of the tailboom assembly in accordance with

paragraph (b) constitutes terminating action for the requirements of

this AD.

(d) An alternative methods of compliance or adjustment of the

compliance time that provides an acceptable level of safety may be

used when approved by the Manager, Rotorcraft Certification Office.

Operators shall submit their requests through an FAA Principal

Maintenance Inspector, who may concur or comment and then send it to

the Manager, Rotorcraft Certification Office.

Note 2: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Rotorcraft Certification Office.

(e) Special flight permits may be issued in accordance with

sections 21.197 and 21.199 of the Federal Aviation Regulations (14

CFR 21.197 and 21.199) to operate the helicopter to a location where

the requirements of this AD can be accomplished.

(f) The inspections and modifications shall be done in

accordance with Bell Helicopter Textron, Inc. Alert Service Bulletin

214ST-95-72, dated July 24, 1995. This incorporation by reference

was approved by the Director of the Federal Register in accordance

with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from

Bell Helicopter Textron, Inc., Attention: Customer Support, P.O. Box

482, Fort Worth, Texas 76101. Copies may be inspected at the FAA,

Office of the Assistant Chief Counsel, 2601 Meacham Blvd., Room 663,

Fort Worth, Texas; or at the Office of the Federal Register, 800

North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on May 10, 1996.

Issued in Fort Worth, Texas, on March 26, 1996.

Larry M. Kelly,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 96-8384 Filed 4-4-96; 8:45 am]

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